Separating-table.



N0. 898,020. PATENTED SEPT. 8, 1908. H. M. SUTTON & W. L. & E. G.STEELE.

I SEPARATING TABLE.

APPLICATION FILED SEPT. 22 1906.

I 7 SHEETS-SHEET 1.

W1 YYVESSLLIS: ff"

No. 898,020. PATENTED'SEPT. 8, 1908. I

H. M. SUTTON & W. L. & E. G. STEELE. SEPARATING TABLE.

APPLICATION FILED SEPT. 22, 1906.

7 SHEETS-SHEET 2.

No. 898,020. PATENTED SEPT. s, 1908.

H. M. SUTTON & W. L. & E. G. STEELE.

' SEPARATING TABLE.

APPLICATION FILE s .22-1906.

D EFT 7SHEE'1S-SHEET a.

No. 898,020. PATENTED SEPT. 8, 1908. -H. M. SUTTON & W. L. & E. G.STEELE.

, SEPARATING TABLE.

, APPLIGATION FILED SEPT. 22, 1906.

7 SHEETS-SHEET 4.

[AWE/Woks hwy/[5212200 21 2 152.36% mm; [0 1)? 6fela lforney 7SHEETS-SHEET 5.

PATENTED SEPT. 8, 1908.

H. M. SUTTON & W. L. & E. G. STEELE.

SEPARATING TABLE.

APPLICATION FILED SEPT.22, 1906.

- PATENTED SEPT. 8, 1908. H. M. SUTTON & W. L. & E. G. STEELE.SEPARATING TABLE.

APPLICATION IILED SEPT. 22, 1906.

7 SHEETS8'HEET 6.

No. 898,020. PATENTED SEPT. 8, 1908.

' H. M. SUTTON & W. L. & E. G. STEELE. SEPARATING TABLE.

APPLICATION IILED SEPT. 22,1906.

7 sums-sum 7.

21' I I m \m q x '11 \\'I//// E\ m u V Q; I Q E F I! N i n 11R F Q U1 llLT N N i W M T WIT/VB 5 [NVE/VTOR-J WM! JIM/6 M! I By UNITED STATESPATENT OFFICE;

HENRY M. SUTTON, WALTER L. STEELE, AND EDWIN G. STEELE, OF DALLAS,TEXAS.

SEPARATING-TABLE T 0 all whom it may concern:

Be it known that we, HENRY M. SUTTON, WALTER L. STEELE, and EDWIN G.STEELE, citizens of the United States, residing at Dallas, in the countyof Dallas, State of Texas, have invented certain new and use ful-Improvements in Separating-Tables, of which the following is aspecification, reference being had therein to the accompanyin drawing.

This invention has relation to a dry concentrating table of that classwhich is employed for the purpose of separating pulverized ore, or otherpulverulent material into its constituent elements, and the objects andadvantages of the invention will be set forth in the followingdescription and its novel features will be particularly pointed out inthe claims.

Heretofore, for example, as shown in U. S. Patent 797,239 granted to usand dated August 15,1905, a dry concentrating table having a pervioustop provided'with riffles and having means for maintaining an upwardpressure of air throu h said pervious top, has been employed for t econcentration of pulverized ore, and one of the objects of thisinvention is to avoid the use of riffles or any other obstructions uponthe upper surface of a pervious table andthereby to facilitate theconcentration or separation, into its constituent elements, of thematerial treated upon the table.

In the further description of this invention and in setting forth thefact that the upper surface of the pervious floor of the table is freefrom obstructions, it is deemed proper to statethat the term obstructionis-intended to in'cludea riflle or any other device or any configurationof the floor which performs or tends to perform the well known functionof, or to produce the result effected by a riflle. .The function of ariffle or obstruction is to subdivide the body of ore upon the tableinto separate bodies in which by the action of gravity or other activeforce the ore, so far as its constituent elements are concerned, assumesthe form of strata, the elements having the greater specific gravityconstituting the lowest strata of the formation.

We have discovered that the presence of riffies or obstructions at orupon the upper surface of the floor of a table are detrimental to asuccessful separation or concentration of the elements of the materialbeing treated,

Specification of Letters Patent.

Application filed September 22, 1906. Serial No. 335,836.

Patented Sept. 8, 1908.

and have therefore devised a pervious table having no riffles orobstructions whatever upon its upper surface whereby we not only utilizethe difierence in the specific-gravity of the elements, but alsoutilizethe difference in What may be termed the frictional-value of theseelements whereby those having slide upon a surface or upon otherparticles of matter. 1

While it is true that specific gravity and frictional-value have acertain relation to each other in that ordinarilyparticles of likegravity would have practically the same frictional-value, othercharacteristics belng equal, still there are numerous exceptions to thisbroad statement caused principally by the formation, shape or otherdistinguishing characteristic between the particles in consideration.For example, garnet and zinc blende have practically the same specificgravity, but garnet is an abrasive material, that is, it is one of thehardest substances known and has sharp edges similar to emery, whilezincblendeon theother hand has slightly rounded edges and is comparativelysmooth and hence has a less frictional valuethan garnet. It thereforefollows that in an application of anu ward pressure of air through thepervious table and through the pulverized ore thereon that the particlesare cushioned on the air and that meeting with no obstructions orriflles in their passage over the floor of said table ample opportunityis afforded for the uninterrupted action of not only the specificgravity but of the frictional frame wor: of the machine with thetableremoved; Fig. 4 is an elevation of the feed end of the machine;Figs. and 6 are details, partly in section, of the table reciprocatingmechanism; Figs. 7 and 8 (Sheet 1) are details of one of the tablesupports; Fig. 9 is a plan of the table with portions of its perviousfloor broken away; Fig. is a longitudinal section on the line AA, Fig.9;'Fig. 11' is a transverse section on the line BB, Fig. 9; Fig. 12 is atransverse section on the line A -A, Fig. 9; Fig. 13 is a transversesection of the table and the air chamber beneath the same; Fig. 14 is alongitudinal section of the table and the air chamber beneath the same;Fig. is a section similar to that shown in Fig. 12 but upon a largerscale; Fig. 16. is a plan of the table showing a modified form thereof;Fig. 16 is a diagrammatic section of floor conformation; Fig. 17 is asection on the line G-G, Fig. 16; Fig. 18 is a detail showing one formof securing the pervious floor in position; Figs. 19, 20, 21, 22, 23 and24 illustrate different methods of producing an undulating unobstructedpervious floor; Fig. 25 is a plan of one form of table with anundulating unobstructed pervious floor; Fig. 26 is a transverse sectionof the floor shown in Fig.

. 25 taken on line H-H; Fig. 27 is still another form of a table havingan undulating unobstructed pervious floor; Fig. 28 is a transverse"section on the line 11 of the floor shown in Fig. 27, and Fig. 29 is atransverse section of the floor shown in Fig. 27

taken on the line J -J 1 (Figs. 1, 2 and 3) designates a suitablefoundation frame work for a concentrating table constructed inaccordance with our invention, and provided with a suitable number ofcross timbers 2, two of which are extended at one side to form thefoundation of uprights 3, 3 for the support of the hopper and itsdriving mechanism.

' 4, 4 are braces for giving rigidity to the uprights 3.

5, 5 are the supports employed upon the lower side of the table. Each ofthese supports is widened at its top and provided with a bearing rod 6which fits the bearing block 7 that is secured in any suitable manner tothe under surface of the table. At its lower end the support 5 has asemicylindrical recess 8 adapted to fit the cylindrical head 9 of athreaded bolt 10 mounted in a bracket 11 whiohis secured to the upper ede and side of the longitudinal beams of the foundation, as clearly shownin Fi 1. The support at the feed end of the tab e is constructedsimilarly to that just described except that its lower end 12 iscylindrical and fits a similarly formed recess in the bearing block 13mounted upon the foundation 1.:

The table at the upper or feed side thereof is supported by the deviceillustrated in Figs.

2 and4. A casting 14 is secured to the under surface of the table and isprovided with a cylindrical head 15 which, with thesocket eeaoao 16 atthe up er end of the connecting link 17 constitute a all and socketjoint.- A similar socket 18 and cylindrical head 19 of the bolt 20constitutes another ball and socket joint. The bolt 20 is mounted in asuitably threaded bracket 21 and has a worm gear 22, Fig. 4, rigidlysecured thereto which is ada ted to be rotated by the worm 23 upon the saft 24, on the end of which is a hand wheel 25 for rotating said shaft,whereby the feed side of the table may be elevated or depressed asdesired. A duplicate bolt 20, worm-gear and worm is provided near thefeed end of the table, as shown. An intermediate bearing 26 serves tomaintain the shaft in a right line.

It will be seen from the description already 1 given that the table isadapted for longitudinal reciprocation without any lateral reciprocationwhatever. This latter feature is insured by the triangular form ofsupports 5 at the lower side of the table.

The means herein shown for giving the longitudinal reciprocation to thetable is but one of many forms which may be adopted.

27, Figs. 1, 2, 3, 4 and 5, represents a casting mounted upon thefoundation and secured thereto in any suitable manner, and comprisingthe bearings 28 of the main shaft 29 carrying the fast and loose pulleys30 and 31 respectively. It also carries the fast pulley 32 for drivingthe feed mechanism in the manner hereinafter described. By reference toFigs. 5 and 6 it will be noted that the main shaft 29 carries aneccentric 33 which is embraced by boxes 34 slidin'gly mounted in a bellcrank lever 35, said lever being mounted u on a fixed pivot 36.

37 is a remova le cover adapted to fit the casting 27 and to inclose thebell crank and its operating mechanism. The shorter arm of the bellcrank is slotted for the rece tion of the block 38 and rendered adjustabe in the slot by the bolt .39 passing therethrough, the block havingtrunnions 40 for the connection therewith of the'yoke 41 (see Fig. 2)with which the table is connected by means of the rod 42 and the bracket43 projecting from beneath the table. The rod 42 is passed through thebracket and is provided with convex washers 44 and lock nuts 45-, toadjust the inclination of the links .17.

The lower central portion of the casting 27 constitutes a hollowchamber, and the bearings 28 are grooved as at 28 to permit the passageof oiling chains 46 over the journals of the main shaft 29 whereby oilis carried up to said journals for lubricating the same. A slot 47 isformed in the cover 37 for the passage therethrough of the yoke 41. 48and 48 are springs, 48" for steadying the motion, and 48 forcounterbalancing the weight of the table as it is supported upon theinclined links 5 and 17, their inclination being toward the feed end ofthe table, and each of said springs 48 provided at its upper end a thelonger arm of the bell crank that the point horizontally opposite thecenter of the secured, while the extension 53 of the spring the pulley32 on the main shaft gives the neceswith an antifriction roller 49contacting with 1 a bracket 50 depending from the table.

51 is a bracket secured to the base and carrying a clamp 52 in which thespring is firmly bears against the adjusting bolt 54 passing through thebracket 55 secured to the base. This provides means for regulating thetension of the springs 48 against the brackets 50. The bracket 56, bestshown in Figs. 1 and 4, of proper conformation is secured to one of thesupports 3 and serves'the purpose of bearings for the shaft 57 carryingthe pulley 58 and provided with any well known crank construction 59which through the medium of connecting rod 60, Fig. 1, serves thepurpose of reciprocating the feed trough 62 of the hopper 63, saidtrough being supported pendulously by rods 64 passing through rackets 65secured to the hopper and having adjusting nuts 66 for regulating thetrough 62 vertically. The hopper 63 is connected with the uprights 3 inany suitable manner. A belt or band passing over the plulley 58 to saryrotation to the crank shaft 57.

As thus far described we have a suitable foundation, a table mountedthereon for longitudinal reciprocation, a hopper above the table with areciprocable trough for delivering material from the hopper onto thetable and suitable devices for adjustin the inclination of the tabletransversely, t e position of the table lengthwise being horizontal sofar as any device thus far described is concerned. It is apparent thatupon the rotation of the main shaft 29 a horizontal reciprocation of thetable will take place, and that by means of the adjustment of the block38 in the short arm of the bell crank 35 the length of the horizontalreciprocation may be adjusted.

It is in the connection of the'shaft 29 with novel feature of thismechanism rests. It will be observed that taking the rotation of theshaft 29 to be in the direction of the arrow, Fig. 6, that as the lon erradius of the eccentric moves from directly over the center of the shaft29 to the right for a distance of 90 that the first effect is to slidethe box 34 toward the pivot ofthe bell crank thus producing a shorterarm which acts from that oint until it reaches a point directly beneatlithe center of the shaft,'29, to quickly depress the long arm of the bellcrank and thus through the connecting rod 42 to quickly return the tabletoward the hopper. The next quarter circle of movement of the long armof the eccentric first efiects a sliding movement of the boxes 34 awayfrom the pivot 36 of the bell crank and to act from a shaft 29to a pointvertically-over said center, as the long arm of the eccentric which actsto advantage secured by this peculiar movement will be hereinafterdescribed.

The construction of the 'body and its top will now be described, itbeing understood that any suitable framework, air chamber and means forsupporting the pervious floor may be employed in lieu of theconstruction herein disclosed. I

By referring to Figs. 2 and 13 it will be noticed that there are aseries of cross bars 67 connecting two side bars 68 which collectivelycomprise the fundamental frame work of the table. Upon the side bars aremounted side pieces 69 and these with the bottom plate 70 constitute theair chamber 71 of the table. I

71'" are flexible air inlet pipes communicating with any suitable sourceof supply to maintain a uniform pressure within the chamber 71. Withinand across the air chamber there are arranged several ribs 72 havingopenings 73 therein to permit access of air under pressure into allparts of the chamber, the purpose of said ribs being to form a supportfor a series of floor supporting ribs 74 which are suitably connectedwith the top frame 75, and the floor supports are bound together bybolts 76, those upon the upper or feed side of the table passing throughand securing in position a retaining or marginal strip 77. The ribs 74extend longitudinally of the table, as shown in Fig. 14, and while theymay be made of separate strips of material assembled edgewise and spacedby blocks 78, as shown in Figs. 19 to 2 1 ,inclusive, a preferable formof construction is to form by a saw or other suitable implefloor of thetable which support is adapted for the passage of air under pressurethrough the slits and grooves or extensions 82 of t e slits through thesolid portion of the plank from which the sections are made. Thesegrooves or extensions provide means for preventing any dead spaces whichprevent the passage of air through the pervious floor. After formingtheslits in the manner just described, the intermediate ribs aretapered, as

clearly shown at 83, said taper being modified in the manner hereinafterdescribed for in Fig. 13 will be had by stating that the right handportion of said figure represents a sec-. tion near the end of the bodywhere the transverse binding bolt or rod passes through the solid wood,while the portion at the left is a vertical transversesection of theribs at the portions where there is no transverse binding rod. The tableis provided with the usua inclined delivery shelves 84 and 85 at thelower side and delivery end, respectively, the former being providedwith a rall 86 sup orted by spacing tubes 87 through which bolts 88 passand by means of nuts 89 passing through brackets 90 secured in' anysuitable manner to the side and end respectively of the body, serve tosecure the parts in operative position, f.

Achannel bar 76 may be attached to stiffen the table if desired. Therail 86 is provided for the purpose of maintainingflemovably, inposition certain fingers 91 main; tained in position by a wedge 92driven between the under surface of the rail and the upper edge ofthefinger whereby the shelf may be divided into sections constitutingchutes or spouts fordirecting the product of the table in its passageover the shelf or shelves.

93 represents What is herein denominated as a pervious floor of thetable, and it consists of any textile material of the desiredweave andfineness of mesh which will permit the passage of air under pressureupward therethrough so as to act upon the body of ore in pulverizedcondition upon the floor. This floor 93 maybe supported upon the upperedges of the ribs 74 in any desired "manner, and its outer margins maybe secured by means of the marginal strip 77 and of the plate 94 alongthe lower edge of the table, said strip and plate acting as a clamp in awell known manner.

Referring to 9 the ervious floor is shown broken away at the eed anddelivery ends of the table. At the feed end there is shown a series ofair retarding stri s 95 which decrease in width from the de ivery sideof the table towards the feed side. These strips are'arranged each uponone of the floor supporting ribs 74, as clearly shown in Fig. 12, andextend longitudinally upon its rib and terminates in a point, each stripbeing tapered throughout its length, and the series of strips terminateon adia onal line extending from one corner to theiagonally oppositecorner of the table. In-other words, the air retarding strips 95' aregradually narrower in width from the corner E to the corner F at thefeed end of the table and termi' nate on a diagonal extending from thecorner C to the corner F of the table. The purtriangular upward andforward portion of the table is also given a novel construction by meansof a series of strips 96 (see Figs. 9 and 11) each mounted upon the rib74 of the same width as the upper surface of the rib, but diminishing inheight from the corner D to the corner C of the table gradually andterminating in the plane of the upper surface of the strips 74successively and collectively along the line extending from the corner Oto the corner F whereby the up er and forward triangular portion of thetab e gradually ascends above the plane of the lower and rear triangularportion thereof for the pulrpose hereinafter to be described.

1%. 15 illustrates one method of securing the or and the air retardingstrips to the supporting ribs 7 4, although any other suit able meansmay be employed. In this in-v stance tacks 97 are driven through thefloor and retarding strips into the u per edge of the supporting ribs.These tac are passed through both the floor and the strips for thepurpose of maintaining contact between the air-.retarding strips and theervious floor being to raise the floor and strip together, asillustrated in exaggerated proportion. in

Fig. 18. It is apparent that if the retarding strips were tacke to theribs independently of the pervious floor the latter might be raised searately from thestrip and therefore pro uce a failure of the function ofthe strip which is to in part restrict the passage of air through thefloor. 1

As thus far described the floor of the table is absolutely'free fromobstructions such as rifles or any device performing the function of arifiie. There 1s, however, as clearly shown in Figs. 1 and 9, a shortbar 98 the purpose of which is to revent the immediate movement ofmateria longitudinally along the'table as it emerges from the deliverychute of the hop er, and it will be noted also by reference to ig. 9that there are no air so that it is an absolutely accurate statementthatthe floor of the table is without ob struc tions because thefunction of the strip 98 has but little to do with the rocess ofconcentrating-or separating the e ementstof the material being treatedinto separated zones, as hereinafter described. 4

The floor of the table thus described is practically flat, but this isno, an essential when the air pressure is applie the tendency,reta-rding strips at that portion of the table characteristic of theinvention. Referring to- Fig. 1 6 it will be seen that if the floor wereformed witha series of Ion itudinal grooves or valleys or inclinedsurraces 99, said surfaces would be when the table is, as a whole,inclined, as it is in use, practically flat in that the point, 99 wouldbe practically on a level with the oint 99 so that no obstruction to thelongitudinal nor to the transverse flow-of material over the table ispresented in this modified form of pervious floor. This form of floormay be produced by securin the floor to the top of the-ribs 74 by thetac s 97 as before described, and by the interposition between the ribsor into or upon alternate ribs, of the plates or bars 100 extendingabove the'upper surface of the .ribs so as to give the grooved orchanneled form of floor illustrated in Fig. 16. The distance above theribs to which said plates or bars project will determine the depth "ofthe grooves of channels, as illustrated in Figs. 19 to 22, inclusive.

Figs. 23 and 24 illustrate diflerent forms of ribs, in which the rib 7 4is tapered from one side only and, used in connection with the unta eredrib 74 produces channels one side of W ich is wider and flatter than theadjacent side, while by the interposition of the fiattopped ribs 74between the ribs 74 channelshaving sides of. equal inclination and areaare produced.

kit

' VVh'en the pervious floor is channeled as just described, or inanyequivalent manner, the channels may terminate on the diagonal line C F(see Fig. 25) as do the. air retarding strips, or they may merge intoan-unchanneled transverse ortion 101, as shown in Fig. 27, at thedelivery end of the table, and these channels may, vary in depth andinclination as indicated in the cross sections shown in Figs. 26, 28 and29', or they may extend the length of the tables There remains stillanother. modification of the means for varying the action of the airunder pressure passing upward through the iioor of the table, and itconsists in constructing the floor of a multiplicity of thicknesses ofcloth, as clearly illustrated in Fig. 16. In this instance there is theupper pervious floor 93 extending wholly over the air chamber of thetable. To the under surface of said floor 93 is secured one thickness oftextile material 102 extending, along the line 102102 then on thediagonal line extending from the corner 0 to near the corner F, to thepoint 102,then along the lower edge of the table to the point 102 thisconstituting a double-thick pervious floor within the area of saidlines. There is next applied to the under surface of the piece 102 apiece of textile material 103 covering the area of the table bounded bythe lineslOS 103 102 and 102 making thus far a ervious floor of threethicknesses over sai area. Then different points of t the air throughthem,

there is applied another piece 104 on the un- ,der surface of the piece103 covering the area included in the'lines 104 104 102 and 102constituting an area of four thicknesses bounded by said lines. Thefunction of these additional thicknesses of pervious flooring is to varythe action of the air upon the material passing over the floor and in amanner somewhat different from that performed by the stri s 95, butstill varying at e floor as a'whole. k,

The air retardin strips could be of sue a density as to totally obstructthe passage of but in such case they are preferably made narrower thanherein shown. This does not produce a different efiect from that hereindescribed for the fol lowing reasons :When in operation the imperviousstrips act to check the body of ore from. moving across the tabletransversely which it would do otherwise under action of the air if thetable was all pervious. When the table is in operation the first part ofthe ore which would be com osed of the lighter minerals (as thesetraveFtransversely faster than the heavier ores) come in contact withthe im ervious strips they are immediately checked in their transversecourse and temporarily detained on the table immediately over one ofthese air retarding strips, owing to the fact that there is no air tomove them, but the heavier minerals, which are also trav eling in parttransversely crowd these lighter minerals from off of these strips aswell as from those portions where the passage of the air through thefloor of the table is restricted, therefore, it is not departing in theleast from the essence of this invention to use impervious strips in thecomposition of the floor er this table. We have found that these strips,if to be used as impervious ones, should be applied in the shape of aintor varnish on the under side of the texti e material forming the floorof the table, as applying it to the top side thereof defeats the objectof the invention because it alters the cloth surface ofthe floor when soapplied asthe frictional value of the textile material is thus alteredor destroyed, unless the character of v material used to renderimpervious the air retarding strips be of such a nature as not to changethe textile surface of the cloth.

By the terms' air controlling, retarding or obstructing strips hereinused we wish to be understood as including strips located at the undersurface of the floor and operat ing-to limit, retard or wholly obstructthe passage of air through the floor at such portions thereof as areprovided with said strips.

The banking strip or bar 98 is intended to initially detain the materialat or near the feed point of the table. This enables the minerals tostratify and emerge at the lower end of the banking strip into separatezones. The material is not positively obstructed by the banking strip asit is placed approximately on the transverse inclination of the tableand does not obstruct theore in the sense of rifiies on this class oftables and does not subdivide the body of ore into separate bodies.

The table is perfectly operative without the banking strip, but in theevent of its bethis efiect at or near the feed, the zones of separatedmaterial become more sharply defined from each other by the time theyhave a is deemed proper to state with further defireached the deliveryside of the table, thereby lproducing cleaner products of each mineraHaving described the mechanical construction of a concentrating orseparating table provided with a pervious floor having no obstructionsupon its upper surface and some modifications in specific forms of saidfloor it niteness the operation of such floor upon the material passingthereover. It is understood that by means of the mechanical adjustingdevices hereinbefore described the table is arranged with the lower sidethereon in nearly a horizontal line, the feed end being slightly lower,and with the feed side in a higher plane so that the whole surface ofthe table is transversely inclined. In this position the natural courseof the material fed upon the floor from the hopper would be u ontransverse lines towards the lower e ge of the floor, and this naturaltendency is, by the longitudinal reciprocation of the table over come tosuch an extent that the path taken. by the ore is practicallyintermediate in direction which is substantially on, or practicallyparallel with, the diagonal line extending from the upper corner at thefeed end to the diagonally opposite corner of the table. Differentmaterials require different adjustment. Now, when the upward pressure ofair is provided through the floor the separation of the various mineralsinto separate bodies or zones is reatly facilitated by the fact that thepartic es are cushioned in the air upon and immediately above the uppersurface of the floor, and by the fact that there are no riffles orconformations of the floor which are equivalent to rifl'les, and whichwould act to destroy or prevent the stratlfication or the arrangement ofthe minerals into distinct The greater distance the minerals can.

or under the influence of the air cushion, and as the heavier particlesof the minerals will always crowd aside or replace a lighter one.

delivered at a different point from that at which the others aredelivered.

Taking Fig. 1 into view the operation of the invention may be stated tobe as fol lows :When the ore is fed from the hopper chute 62 it fallsupon that portion of the floor where there are no air retarding strips,and

under the cushioning action of the air the minerals stratify themselvesaccording to weight by reason of their temporary detention at that pointby the short banking strip or bar 98. The. heaviest mineral remains nextto or upon the cloth floor, the next heaviest above that andthe'lightest upon the top, the Stratification assumes an angle to thesurface of the floor, and as the particles of ore are cushioned fromeach other, and the strata likewise, the inclination which the stratahave assumed causes them to slide each from ofi the other so that at thelower corner of the banking strip 98 the different minerals begin toform into zones and each takes a we 1 defined path more or less diagonalalonggreatest frictional value, causes it to be more sluggish in itsmovement than the other minera as the others, consequently it is thelast to make its appearance at the lower corner of the banking strip.During the first few moments of the operation of the table the gangue'orlighter minerals spread over the entire surface of the floor. The firstof the heavy minerals to make its appearance at the lower corner of thebanking strip 98 is the zinc which begins to crowd the gangue to therear. Next the iron makes its ap earance and begins to crowd the zinc,and ast, the lead which crowds the iron so that after the table has beenrun for a short time it presents the appearance shown in Fig. 1. Thiswhole action is due to the difference in frictional value or mobility ofthe particles which is utilized by cushioning the particles in the air.As stated the lead is more slug ish and less mobile than the otherpartic es and travels across the floor more longitudinally, and in oneform illustrated in Fig. 9 the upper "diagonal half of the table israised by means of the strips 96 in order to make the minerals take amore diagonal course.

being mobile and freer to. move than the lead takes a ath across thefloor in a line affording the east resistance which. is naturally a zoneapproximately parallel to the lead ore, and on account of the freermobility of itsparticles they are unable to climb up on thesteeper'portion of the floor occupied by the lead. The fact that theytravel at a different rate of speed will prevent them, interminglingwith other minerals. The same is true with the iron in its effect uponthe zinc and the zinc upon the gangue. v The air retarding stri s beingpreferably of a textile material 0 less porosity than the materialconstituting the floor of the table act to perform the functionindicated by the name given them, but they also by reason of theirtapered form provide unobstructed passages extending longitudinally ofthe table and increasing in area from the feed end toward the deliveryend. The" action of these air retarding strips upon all minerals orparticles is in proportion to their weight. The air passing throughthese air retarding strips is reduced in pressure and insufficient Imovement of the table than the lighter ones to cushion the heavierminerals. The result is to check their transverse movementand thereforethey become more affected by the longitudinal'movement of the table. Thelight minerals on the other hand are sufficiently cushioned by the airso that they meet with comparatively little resistance. As these areremoved the strips increase in width and as the pulp travelstransversely the next'heavier minerals begin to be affected, and just inproportion as these minerals are checked during the transverse movementso do they take up a longitudinal movement imbplarted to them by thereciprocation ofthe ta e.

Another important feature of the operation is that while the table is inoperation the pulp is resting u on an elastic cushion of air. When thetab e is raised in its forward movement the air cushion sufiers more orless compression-and thus causes the heavier particles to come intocontact with the surfaceof the floor of the table sooner and remain incontact with it longer on .the return and to this fact is due also thedifierence in the rate of speed at which the particles travel.

It remains to show the action of the modi-v ficationsin the superficialoutline 'of the floor of the table. It is apparent that when said flooris formed into longitudinal channels 99 that the practical effect is togive a greater superficial .area to the floor of the table of givendimensions as compared with a practically flat floor of the same table.The

transverse inclination of the table does not render thechanneled-surface the equivalent ofa riffle or other obstruction becauseofthe fact that the longitudinal movement is un- W obstructed, and thereis also a somewhat different ap lication of the air pressure to themateriaFupon the inclined sides ofthe channel. These channels may, ofcourse, be either continuous and of uniform or varying area in crosssection or it is clear that they may be of varied area in cross sectionand terminate either upon a diagonal or a straight transverse linewithin the area of-the floor, as illustrated in Figs. 25 to 29,inclusive.

The modification shown in Fi 16 clearly provides means for varying t eeffective force of the air in its passage through the floor of thetable, a function which is erformed by the strips 95 in Fig. 1 as wel asby the channel forms of floor hereinbefore described.

In all of these various forms of the floor of the table there isprovided means for utilizing not only the difference in specific gravityexisting in the particles, but also for utilizing the differences infrictional value existing in these particles, and the utilization ofthese characteristics inherent in the particles demands the absence ofany obstructions which interfere with the proper stratification and theproper cushioning action by the air whereby regulated transversemovements of the particles u on the transversely inclined table issecure in proportion to the weight of the particles, and in proportionto'their frictional value. zation of the frictional value of theparticles that a cushioning action of the air must be present in orderto permit the frictional value to operate upon the floor or otherparticles.

Another feature of the o eration of an unobstructed pervious floor avingair retardft is essential to the utiliing means arranged beneath saidfloor, or

havinga channeled conformation to modify thecushioning function of theair, is that when the table is raised and forwarded in its forwardreciprocation, the air cushion suffers more or less compression whichcauses the heavier particles to contact with the floor sooner and remainin contact therewith longer, on the return movement of the table, thanthe lighter particles and to this fact is due the difference in rateofspeed at which different particles travel: The variable widths, lengths,thicknesses, and areas of the various air retarding means shown, and thevaried conformation of the pervious fioor varies the cushioning functionof the air in that it diminishes transversely and increaseslongitudinally at all points 'of the floor included by or immediatelyadjacent thereto. Thus the cushioning function is more closely movementover the table.

' on and over the surface of the floor, and to the inherent specificgravity and frictional value of the particles so that a finer, moreexact and more complete separation is insured.

It is apparent that the effectiveness of the upward pressure of airthrough our pervious floor is varied by the retarding strips, Fig. 9,the multi le thicknesses of textile material shown in liig. 6, and bythe channel construction, Figs. 26 and 27, especially in the latter, inthat the meshes of the fabric are at an angle to the current of air,which is preferably continuous, and hence it is retarded and does not sostrongly and directly act upon the material u on the upper surface ofthe floor as When't e meshes are in line with the movement of the air."In fact, each side of a channel may be considered an unobstructed floorof limited area on which the rocess of se aration according to frictionavalue is ta 'ng place. K

It is a parent that many changes, additions and omissions of minordetails herein shown may be made within the range of me chanical skillwithout a departure from the fundamental principles of our invention,and therefore we do not limit our invention in these particulars, but

What we do claim is 1. A concentrating table having a floor free'fromobstructions and impervious to the passage of materialtherethrough'while pervious to air under pressure, in combination withmeans for passing air through said floor, means for causing the heavierand lighter materials to travel in divergent paths, and separated aircontrolling strips secured in contact with the under surfaceof saidfloor and disposed to form intermediate continuous air passagesextending substantially transversely to the path of travel of therelatively lighter components of the material thereon.

2. A concentrating, table having a floor free from obstructions andimpervious to the passage of material therethrough while pervious to airunder pressure, in combination with means for pass ng air through saidfloor, and separated air controlling strips each having a taperedoutline secured in contact with the under surface of said floor anddisposed transversely to the path of travel of a rela'- tively lightercomponent of the material thereon.

3. A concentrating table having a floor free from obstructions andimpervious to the passage of material therethrough while pervious to airunder pressure, in combinationv with means for passing air through saidfloor, and controlling means extending transversely to the path oftravel of a relatively lighter component of the material thereon andgradually varying the width throughout the length thereof.

4. A concentrating table having a floor .free from obstructions andimpervious to the passage "of material therethrough while pervious toairunder pressure, in combination with means for passing air throughsaid floor, and separated air controlling strips secured in contact withthe undersurface of said floor and disposed transversely to the path oftravel of a relatively lighter component of the material thereon, saidtable being provided with an uncontrolled area beyond the longitudinaltermini of the strips.

5; A concentrating table having a floor free from obstructions andimpervious tothe passage of material therethrough while pervious to airunder pressure, means for causing the heavier and the llghter materialsto travel in divergent paths thereon, in combination.

with means for passing air through said floor, and means disposedtransversely to the path of travel of the relatively lighter componentof the material thereon for controlling the effectiveness of said airressure through said floor in different lines ongitudinally of thetravel of the heavier comonents.

6. A concentrating ta le having a floor free from obstructions andimpervious to the passage of material therethrough while pervious to airunder pressure, means for. causing the heavier. and the lightermaterials to travel in divergent paths'thereon, in combination withmeans for passing air through said floor, and means for rendering saidair pressure decreasingly eflective transversely of the path of travelof a relatively lighter component of the material upon the floor.

7. A concentrating table having a floor free from obstructions andimpervious to the passage of material therethrough while pervious to airunder pressure, means for causing the heavier and the lighter materialsto trave in divergent paths thereon, in combination with means forpassing air through said floor, means for rendering the air pressurethrou h said floor increasingl effective transverse y of the path oftrave of a relatively lighter component of the material thereon and in1' parallel separated spaces.

8. A concentrating table having a floor free from obstructions'andimpervious to the passage of material therethrough while perwith meansfor passing. air through said floor,

and means for rendering said air pressure 1 vious to air under pressure,in'combination 1 component of the r'naterialthereon and increasinglyeffective longitudinally of said path and in parallel separated spaces.

9. A floor for a'cone'entrating table ime pervious to the passage ofmaterial therethrough and pervious to air under pressure and having taered air controlling strips differing in Widlfil at the feed end of thefloor and disposed transversely of the path of travel of a relativelylighter component of the material thereon.

10. A floor for a concentrating table impervious to the passage ofmaterial therethrough and pervious to air under pressure and havingtapered air controlling strips differing in width at the feed end of thefloor and disposed transversely of the path of travel of a relativelylighter component of the material thereon and merging into an area freefrom air controlling means;

11. A floor for a concentrating table impervious to the passage ofmaterial therethrough and pervious to air under pressure and having taered air controlling strips differing in widt at the feed end of thefloor its lower surface terminating in a diagonal line and having atriangular portion at the delivery end of the floor upwardly inclinedfrom the remaining portion thereof and free from air controlling strips.

13. Ina concentrating table, a floor in- -clined transversely to thepath of travel of. one of the components {of the material thereon andfree from obstructions and impervious to the passage of materialtherethrough while pervious to air under ressure, in combination with anair cham er beneath said fioor and means for supplying air thereto,means for reciprocating said table, and sep arated air controlling.means secured in contact withthe under surface of said floor anddisposed transversely of the path of travel of a relatively lightercomponent of the material thereon.

14. In a concentrating table, an unobj-,

structed floorimpervious to the passage of material therethrough andpervious to air under pressure, .said floor being inclined laterally andlongitudinally relatively to the path of travel of one component of thematerial thereon,'separated air obstructing means secured upon theunderface of said floor and disposed transversely of the path of travelof a relatively lighter component of the material thereon, and means forpassing air through said floor.

15. In a concentrating table, an unobstructed floor impervious to thepassage of material therethrough and pervious to airunder pressure, saidfloor being inclined latererally relatively to the path of travel of onecomponent. of the material thereon, separated air obstructing meanssecured upon the under face of said floor and disposed transversely ofthe path of travel of a relatively lighter component of the materialthereon, an air chamber beneath said -floor, and means for oscillatingsaid floor upwardly in a vertical plane at a less speed than in itsreturn move ment.

16. A concentrating table having a floor free from obstructions andimpervious to the passage of material therethrough while pervious trrairunder pressure, means for passing 'air through said floor, separated airretarding strips secured upon the under surface of said flo or anddisposed to form intermediate continuous air passages extendingsubstantially transversely to-the pathof travel of a relatively lightercomponent of the material thereon, a hopper to deliver material at oneend of said floor, and a bar arranged transversely of the floor inproximity to said hopper to prevent immediate longitudinal movement ofthe material over said floor.

/ 17. A concentrating table having a floor free from obstructions andimpervious to the passage of material therethrough while pervious to airunder pressure, in combination with means for passing air through saidfloor, separated air controlling strips secured'in contact with theunder surface of said floor and disposed to form intermediate continuousair passages extending substantially I transversely to the path oftravel of the relatively lighter components of the material thereon, andmeans for reciprocating said table longitudinally of the air controllingstrips thereon.

In testimony whereof, we aflix our. signatures in presence of twowitnesses. v

HENRY M. SUTTON. WALTER L. STEELE. EDWIN ,G. STEELE.

Witnesses:

O. H..BEHRENS, Dozaa MQMAHAN.

